Balance training device

ABSTRACT

The present invention realizes a balance training device usable for training a capability of balancing with a user carried thereon in a standing posture or a sitting posture without the need for any complicated linkage mechanism, said device comprising: a plate ( 1 ) for carrying a user; a motor ( 2 ) for driving said plate; a sensor ( 3 ) for measuring a rotation angle of said plate; a torque measuring mechanism (including a pair of force plates  41 ) for measuring a torque applied to said plate; a kinetic model analyzer ( 5 ) for determining a target rotation angle for said plate ( 1 ) from said measured torque; and a motor controller ( 6 ) for controlling said motor in accordance with a predetermined kinetic model.

FIELD OF THE INVENTION

The present invention relates to a balance training device for trainingthe sense of equilibrium of a user by swinging a plate with a usercarried thereon.

DESCRIPTION OF THE PRIOR ART

There is a known device according to a prior art as an activelyoperating balance training device, including one directed to anapplication in a sitting posture (see, for example, Japanese PatentPublication No. 2000-102523) and another having a complicated linkagemechanism (see, for example, Japanese Patent Publication No.2001-286578).

Such an actively operating balance training device of the prior art hasa drawback that it can provide only the training in the sitting posturefor a user but it is difficult to provide the training in the legsegment, which is essential to control the sensible balance. There isanother problem in association with such a device of the prior art thata mechanism for controlling a swing motion is complicated, as it hasemployed a plurality of linkages, for example, thus being subject to ahigher risk of failure of the device. The device of the prior art hasbeen also associated with another drawback that it is unable to providethe training independently and exclusively directed to each of threeorgans, including a semicircular canal, a vision and a deep sensibility,each governing a personal sense of equilibrium.

An object of the present invention is, on the premise of its use in astanding posture for realizing the training in the leg segment, toprovide a balance training device that allows a motion of a plate with auser carried thereon to be achieved in the form of a rotation in thelateral direction with respect to the body of the user while eliminatinga need for any complicated linkage mechanism. Another object of thepresent invention is to realize the specified training that may beprovided independently and exclusively directed to each of the threeorgans, including the semicircular canal, the vision and the deepsensibility, each governing the personal sense of equilibrium.

The term “deep sensibility” used herein refers to the sensibility torecognize a position for a certain part to be taken relative to otherparts of a body of a person experiencing the training and the deepsensibility is classified to a proprioceptive sensibility. The deepsensibility is provided by the receptors, including a contact pressurereceptor of skin, a muscle spindle, a pacinian corpuscle of subcutaneoustissue and a neural free terminal (cited from: “Medical Dictionary, 2ndEdition”, Ishiyaku Publishers Inc., 1996).

SUMMERY OF THE INVENTION

According to an aspect of the present invention, provided is a balancetraining device usable in a standing posture or a sitting posture, saiddevice comprising: a plate 1 for carrying a user; a motor 2 for drivingsaid plate 1; a sensor 3 for measuring a rotation angle of said plate; atorque measuring mechanism for measuring a torque applied to said plate;a kinetic model analyzer 5 for determining a target rotation angle forsaid plate from said measured torque; and a motor controller 6 forcontrolling said motor in accordance with a predetermined kinetic model.

The balance training device of the present invention may becharacterized in that said plate 1 is rotated around an axis of rotationextending in parallel with a top surface of the plate.

The balance training device of the present invention may have aconfiguration in which said top surface of said plate 1 coincides with aplane containing a center of the axis of rotation.

The balance training device of the present invention may have aconfiguration in which said top surface of said plate 1 is spaced apartby a certain distance from the center of the axis of rotation.

The balance training device of the present invention may have aconfiguration in which said torque measuring mechanism has a pair offorce plates 41 each comprising an integrated sensor unit composed ofone sensor for measuring a load applied to said plate 1 and the othersensor for measuring a position of a center of loading.

The balance training device of the present invention may have aconfiguration in which said torque measuring mechanism comprises asensor 42 for measuring a torque applied to said plate 1, which ismounted on a shaft of the motor 2 for driving said plate 1.

The balance training device of the present invention, in oneconfiguration, may have a kinetic model analyzer 5 characterized in thata motion of said plate 1 is defined by a spring constant, a viscousbraking coefficient and a moment of inertia, all of which are virtual.

The balance training device of the present invention, in oneconfiguration, may have a motor controller 6 for controlling the plate 1with a user carried thereon in accordance with an angle of equilibriumthat has been arithmetically determined by said kinetic model analyzer5. The term “angle of equilibrium” used herein refers to an angle makingthe force applied by the user in balance with the rotational force ofthe motor. Increasing or decreasing of the rotational force will modifythe angle of making the equilibrium.

Said balance training device of the present invention can provide thetraining independently and exclusively directed to each one of threeorgans, including the semicircular canal, the vision and the deepsensibility, each governing a personal capability of balancing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view illustrating an embodiment of abalance training device according to the present invention;

FIG. 2 is a perspective view illustrating an embodiment of a balancetraining device according to the present invention, showing an exampleincluding a rotation torque sensor mounted thereon;

FIG. 3 is a block diagram for controlling a measuring operation and amotor in an embodiment of a balance training device according to thepresent invention;

FIG. 4 is a schematic perspective view for facilitating theunderstanding of equations (1) and (2) for arithmetically determining arotation torque and a kinetic analytical model for an embodiment of abalance training device according to the present invention; and

FIG. 5 provides a graphical representation of simulation results fordifferent viscous braking coefficients with respect to an embodiment ofa balance training device according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of a balance training device according to thepresent invention will now be described on the basis of some exampleswith reference to the attached drawings. FIG. 1 is a perspective viewillustrating a first embodiment of the balance training device accordingto the present invention. This balance training device allows fortraining independently directed to each one of three organs, including asemicircular canal, a vision and a deep sensibility, each governing apersonal capability of balancing, in which a user carried on a plate ofthe device is subject to the swing motion of the plate, and also isallowed to take an active motion in a standing posture or a sittingposture to thereby train his/her capability of balancing.

The balance training device comprises a plate 1 for carrying a user 4thereon, a motor 2 for driving the plate 1, a rotation angle sensor 3for measuring a rotation angle of the plate 1, a torque measuringmechanism for measuring a torque applied to the plate 1, a kinetic modelanalyzer 5 for determining a target rotation angle from the measuredtorque, and a motor controller 6 for controlling the motor in accordancewith a predetermined kinetic model. The torque measuring mechanism mayemploy a pair of force plates 41 each serving for measuring a forceapplied onto the plate 1 by a left or a right foot, respectively, andthen calculate the torque based on the measurements, or may employ acommercially available torque sensor 42 mounted on a revolving shaft ofthe motor 2, which will be described later.

A clamp 7 is attached to the plate 1 in a central location of a rearedge thereof along its width direction so as to clamp the plate 1. Therevolving shaft of the motor 2 is fixedly attached to a back surface ofthe clamp 7 appropriately with a fastening means so that the center ofthe revolving shaft of the motor 2 may be positioned at the center ofthe plate 1 along its width direction and in parallel with a top surfaceof the plate 1.

In this arrangement, the revolving shaft of the motor 2 may be fixedlyattached to the back surface of the clamp 7 such that a center of axisof rotation of the revolving shaft is positioned on a plane of the topsurface of the plate 1, or in an alternative configuration, such thatthe center of axis of rotation of the revolving shaft is spaced apartfrom the plane of the top surface of the plate 1 by a certain distance.This arrangement allows for the plate 1 to make a swing motion aroundits revolving shaft when the user carried thereon take a motion and alsoto provide a tilting motion in an active manner by means of the motor 2.The motor 2 is adapted to be actuated and controlled externally.

The torque measuring mechanism may be one configuration employing thepair of force plates 41 as shown in FIG. 1 or may be the otherconfiguration employing the commercially available rotation torquesensor 42 as shown in FIG. 2, as already discussed above.

In FIG. 1, the torque measuring mechanism using the pair of force plates41 comprises the pair of force plates 41 and an arithmetic processingunit (not shown). The plate 1 includes the pair of force plates 41 eachpositioned on its top surface in the left and the right sidesaxi-symmetrically with respect to the revolving shaft. Each of the forceplates 41 comprises an integrated set of two sensors, including one formeasuring a load applied to the plate 1 and the other for measuring aposition of the center of loading when the user takes any motions ascarried on the plate 1.

The arithmetic processing unit may calculate the torque by multiplying ameasurement of the pair of force plates 41 (load applied to the centerof the loading) by a certain distance defined by an offset of the centerof the loading from the center of axis of rotation of the revolvingshaft (force X distance).

In FIG. 2, the configuration employing the commercially availablerotation torque sensor allows for the rotating force (torque) applied tothe plate from the motion of the user to be measured by means of acommercially available rotation torque sensor that has been attached tothe revolving shaft of the motor 2.

The rotation angle sensor 3 as shown in FIG. 1 is mounted to the clamp7, which has clamped the plate 1 at its front edge thereby to beattached thereto, and adapted to measure a rotation angle as the plate 1is tilted.

FIG. 3 shows a block diagram illustrating a general configuration forcontrolling the motor by the torque measuring mechanism, the rotationangle sensor, the kinetic model analyzer and the motor controller. InFIG. 3, respective components are connected to each other in such amanner that an output from each of the torque measuring mechanism andthe rotation angle sensor 3 is input to the kinetic model analyzer 5, anoutput from the kinetic model analyzer 5 is in turn input to the motorcontroller 6, and an output from the motor controller 6 is then input tothe motor 2.

With the configuration shown in FIG. 3, the kinetic model analyzer 5determines a rotation angle of the plate 1 which may vary in dependenceon the force applied to the plate 1 defined by the equation (1) as shownbelow, which is associate with FIG. 4 for easy understanding, thusproviding the control of the motor 2.J{umlaut over (θ)}+D{dot over (θ)}+kθ=T _(m) +T _(d)  (1)

where

-   -   θ: Rotation angle of the plate (rad);    -   J: Moment of inertia (kg·m²);    -   D: Viscous braking coefficient (N·s/m);    -   K: Spring constant (N/m);    -   T_(m): Rotation torque (N·m); and    -   T_(d): Disturbance torque (N·m)

An operation of a balance training device according to the presentinvention that has been constructed to have the above-describedconfiguration will now be described. As a user puts herself/himself onthe plate 1 of the balance training device, unstable balancing abilityof the user causes the plate 1 to be tilted and thus rotation (swingmotion) to be produced. The user then realizes the tilting due to therotation and attempts to apply the force to either one of his/her feetto compensate for the tilting. This may cause the force to exert againstsaid rotation to trigger the rotation of the plate in the oppositedirection, thus carrying out a series of operations.

During this series of operations, the motor is controlled by using theforce applied by the user and the rotation angle of the plate 1 asvariable parameters under the condition of the rotation characteristicsof the plate 1 defined by the spring constant, the viscous brakingcoefficient and the moment of inertia, which are all virtual as shown inFIG. 4, and thereby the device can provide the training accordingly independence on the high or low level of performance in the capability ofbalancing of the user. Further, a certain magnitude of rotation may beapplied to the plate 1 as the disturbance. That is, the device alsoallows for the training intended to respond to any external stimulationby applying the disturbance torque to the device.

Specifically, the user steps onto the device with his/her feet incontact with the plate 1 and attempts to make a balance as much aspossible so as not to lean laterally with respect to the body of theuser. The rotation angle of the plate 1 in the lateral direction withrespect to the user's body is measured by the angle sensor 3 while therotation torque of the plate 1 is measured by the rotation torquemeasuring mechanism, and the measured values are supplied to the kineticmodel analyzer as shown in FIG. 3. To determine the rotation torque, theforces applied by the left and the right feet onto the plate 1 aremeasured by the pair of force plates 41 respectively and the rotationtorque is calculated with the arithmetic processing unit by applying themeasured force values to the equation (2) as shown below, which isassociate with FIG. 4 for easy understanding, and thus calculatedrotation torque value is supplied to the kinetic model analyzer as shownin FIG. 3. Alternatively, the rotation torque may be measured by therotation torque sensor 42 and the measured value may be supplied to thekinetic model analyzer.

In use of the pair of force plates, the rotation torque, T_(m), iscalculated in the following equation:T _(m) =L(F _(r) −F _(l))cos θ  (2)where:

-   -   T_(r): Force applied to the plate by the right foot (N);    -   T_(l): Force applied to the plate by the left foot (N); and    -   L: Distance from the revolving shaft to the force plate (m).

The kinetic model analyzer, by using the equations (1) and (2),calculates an angle of equilibrium (an angle making the force applied bythe user in balance with the rotating force of the motor) of the plate1, which may vary in dependence on the forces applied to the plate 1, toprovide the appropriate control so that the motor 2 is rotated to swingthe plate 1 and thus to provide the balance training for the user. Thatis, the angle of equilibrium may be modified by increasing or decreasingthe rotating force of the motor, and the user tries making a balance toachieve thus modified angle of equilibrium, thereby effecting thebalance training to be provided.

It is to be noted that in the above equations (1) and (2), the values ofthe viscous braking coefficient and the spring constant are those havingbeen virtually introduced in the calculator (kinetic model analyzer)when determining the angle of equilibrium, and those values are knownwhen the control is provided. It is further appreciated that thedisturbance torque value represents the amount to be given by thecontroller when the angle of equilibrium is determined, and it is aknown value. Therefore, the measurement of the rotation angle and therotation torque can provide the calculated value for the angle ofequilibrium, as discussed above.

Further, the training can be performed independently and exclusively oneach one of three organs, including the semicircular canal, the visionand the deep sensibility, each governing a personal capability ofbalancing, by blocking the visual information, restricting the rotationof the head segment or locking the leg segment (ankle, knee joint) inthe immobilized state during the training.

FIG. 5 shows graphical representations of the simulation resultsillustrating how the rotation torque and the rotation angle vary overtime in conjunction with the change in viscous braking coefficient forthe high or low level of performance in respective personal capabilityof balancing. Both of D015E80 and D015E95 represent the cases with therelatively small viscous braking coefficient, one plotting the variationfor the relatively low level of performance in the personal capabilityof balancing, the other plotting the variation for the relatively highlevel of performance in the personal capability of balancing, while bothof D100E80 and D100E95 represent the cases with the relatively greatviscous braking coefficient, one plotting the variation for therelatively low level of performance in the personal capability ofbalancing, the other plotting the variation for the relatively highlevel of performance in the personal capability of balancing. It is tobe noted that each of D015E80, D015E95, D100E80 and D100E95 simplydesignates the reference numeral for the data illustration.

It can be seen from FIG. 5 that the variation in the rotation angle isgreater with the smaller viscous braking coefficient, while thevariation in the rotation angle is smaller with the greater viscousbraking coefficient. It is further seen that the higher level ofperformance in the personal capability of balancing can adjust therotation angle with a smaller rotation torque.

The balance training specified in the semicircular canal is feasible byblocking the visual information and restricting the motions in the legand body trunk segments during training.

The balance training specified in the vision is feasible by restrictingthe motions in the head, body trunk and leg segments and providing avideo image of the external world in synchronism with the rotation angleof the plate during the training.

The balance training specified in the deep sensibility using muscle inthe body trunk segment is feasible by blocking the visual information,restricting the head segment and restricting the motion in the legsegment during the training.

The balance training specified in the deep sensibility using joint andmuscle in the leg segment is feasible by blocking the visualinformation, restricting the head segment and restricting the motion inthe body trunk segment during the training.

The blocking of the visual information may be achieved by covering eyeswith a blinder, for example.

The restricting of the head/body trunk segment may be achieved byplacing the armpits on the bars, such as hand-rails, with the bodyleaning against the bars.

The fixedly locking of the leg segment may be achieved with a certaintype of assist tool inhibiting the bending motion in the ankle and/orthe knee joint, which is mounted in the leg segment so as to prevent themovement and/or rotation thereof relative to the plate 1. It may be alsofeasible by the user taking the sitting posture.

Although the present invention has been described in the illustratedembodiments, the present invention is not limited to those embodimentsbut many variations thereof will be apparent to those skilled in the artwithout departing from the technical scope defined in the appendedclaims.

INDUSTRIAL APPLICABILITY

The balance training device according to the present invention, owing toits configuration as described above, can achieve the rotation of theplate with a user carried thereon in the lateral direction with respectto the body of the user while eliminating the need for any complicatedlinkage mechanism. Further, the balance training device of the presentinvention is suitably applicable as a training device allowing for thetraining independently and exclusively directed to each one of the threeorgans, including the semicircular canal, the vision and the deepsensibility, each governing a personal capability of balancing.

1.-9. (canceled)
 10. A balance training device usable in a standingposture or a sitting posture, said device comprising: a plate forcarrying a user; a motor for driving said plate; a sensor for measuringa rotation angle of said plate; a torque measuring mechanism formeasuring a torque applied to said plate; a kinetic model analyzer fordetermining a target rotation angle for said plate from said measuredtorque; and a motor controller for controlling said motor in accordancewith a predetermined kinetic model.
 11. A balance training device usablein a standing posture or a sitting posture in accordance with claim 10,in which said plate rotates around an axis of rotation extending inparallel with a top surface of said plate.
 12. A balance training deviceusable in a standing posture or a sitting posture in accordance withclaim 11, in which said top surface of said plate coincides with a planecontaining a center of the axis of rotation.
 13. A balance trainingdevice usable in a standing posture or a sitting posture in accordancewith claim 11, in which said top surface of said plate is spaced apartby a certain distance from said center of the axis of rotation.
 14. Abalance training device usable in a standing posture or a sittingposture in accordance with claim 10, in which said torque measuringmechanism has a pair of force plates each comprising an integratedsensor unit composed of one sensor for measuring a load applied to saidplate and the other sensor for measuring a position of a center ofloading.
 15. A balance training device usable in a standing posture or asitting posture in accordance claim 10, in which said torque measuringmechanism comprises a sensor for measuring a torque applied to saidplate, which is mounted on a shaft of said motor for driving said plate.16. A balance training device usable in a standing posture or a sittingposture in accordance with claim 14, in which said device has a kineticmodel analyzer characterized in that a motion of said plate is definedby a spring constant, a viscous braking coefficient and a moment ofinertia, all of which are virtual.
 17. A balance training device usablein a standing posture or a sitting posture in accordance with claim 10,in which said device has a motor controller for controlling said platewith a user carried thereon in accordance with an angle of equilibrium,or an angle making the force applied by the user in balance with theforce provided by said motor, that has been arithmetically determined bysaid kinetic model analyzer.
 18. A balance training device usable in astanding posture or a sitting posture in accordance with claim 10, inwhich said balance training device can provide the trainingindependently and exclusively directed to each one of three organs,including a semicircular canal, a vision and a deep sensibility, eachgoverning a personal capability of balancing.
 19. A balance trainingdevice usable in a standing posture or a sitting posture in accordancewith claim 11, in which said torque measuring mechanism has a pair offorce plates each comprising an integrated sensor unit composed of onesensor for measuring a load applied to said plate and the other sensorfor measuring a position of a center of loading.
 20. A balance trainingdevice usable in a standing posture or a sitting posture in accordanceclaim 11, in which said torque measuring mechanism comprises a sensorfor measuring a torque applied to said plate, which is mounted on ashaft of said motor for driving said plate.
 21. A balance trainingdevice usable in a standing posture or a sitting posture in accordancewith claim 15, in which said device has a kinetic model analyzercharacterized in that a motion of said plate is defined by a springconstant, a viscous braking coefficient and a moment of inertia, all ofwhich are virtual.
 22. A balance training device usable in a standingposture or a sitting posture in accordance with claim 11, in which saiddevice has a motor controller for controlling said plate with a usercarried thereon in accordance with an angle of equilibrium, or an anglemaking the force applied by the user in balance with the force providedby said motor, that has been arithmetically determined by said kineticmodel analyzer.
 23. A balance training device usable in a standingposture or a sitting posture in accordance with claim 14, in which saiddevice has a motor controller for controlling said plate with a usercarried thereon in accordance with an angle of equilibrium, or an anglemaking the force applied by the user in balance with the force providedby said motor, that has been arithmetically determined by said kineticmodel analyzer.
 24. A balance training device usable in a standingposture or a sitting posture in accordance with claim 15, in which saiddevice has a motor controller for controlling said plate with a usercarried thereon in accordance with an angle of equilibrium, or an anglemaking the force applied by the user in balance with the force providedby said motor, that has been arithmetically determined by said kineticmodel analyzer.
 25. A balance training device usable in a standingposture or a sitting posture in accordance with claim 16, in which saiddevice has a motor controller for controlling said plate with a usercarried thereon in accordance with an angle of equilibrium, or an anglemaking the force applied by the user in balance with the force providedby said motor, that has been arithmetically determined by said kineticmodel analyzer.